-Shut computer down
-Restart, hit F8 right away, select Safe Mode with Networking
-Go to http://malwarebytes.org, download the latest version of Malwarebytes and run a full scan
At this point the virus should be gone, but to be sure:
-Go to http://download.com, get the latest version of 'hijack this! '
-Run it, perform a scan and save the Results file
-Upload the Results file to http://hijackthis.de , it will give you an analysis and further advice ( if the site is too busy, you will not see the Analyze button and will have to wait)